KMSAN: uninit-value in __fget

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KMSAN: uninit-value in __fget_light (2) fs	7	C			18	1884d	1893d	15/29	fixed on 2020/11/16 12:12
upstream	KASAN: null-ptr-deref Read in __fget_light fs	11				4	1668d	1763d	0/29	auto-closed as invalid on 2021/09/30 22:37

================================================================== BUG: KMSAN: uninit-value in atomic64_add_unless arch/x86/include/asm/atomic64_64.h:204 [inline] BUG: KMSAN: uninit-value in __fget fs/file.c:693 [inline] BUG: KMSAN: uninit-value in __fget_light+0x5fb/0x710 fs/file.c:740 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 8706 Comm: syz-executor0 Not tainted 4.16.0+ #86 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683 atomic64_add_unless arch/x86/include/asm/atomic64_64.h:204 [inline] __fget fs/file.c:693 [inline] __fget_light+0x5fb/0x710 fs/file.c:740 __fdget+0x4e/0x60 fs/file.c:748 fdget include/linux/file.h:57 [inline] do_pollfd fs/select.c:816 [inline] do_poll fs/select.c:877 [inline] do_sys_poll+0x10b7/0x20e0 fs/select.c:971 SYSC_poll+0x2d2/0x560 fs/select.c:1029 SyS_poll+0x54/0x80 fs/select.c:1017 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x455389 RSP: 002b:00007f4c1084ac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000007 RAX: ffffffffffffffda RBX: 00007f4c1084b6d4 RCX: 0000000000455389 RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000020000040 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000046b R14: 00000000006f9aa8 R15: 0000000000000000 CPU: 1 PID: 8711 Comm: syz-executor1 Not tainted 4.16.0+ #86 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 __kmalloc+0x23c/0x350 mm/slub.c:3791 Call Trace: kmalloc include/linux/slab.h:517 [inline] sock_alloc_inode+0xb9/0x2b0 net/socket.c:247 alloc_inode fs/inode.c:209 [inline] new_inode_pseudo+0x8a/0x430 fs/inode.c:890 __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 sock_alloc net/socket.c:565 [inline] __sock_create+0x392/0xf60 net/socket.c:1249 sock_create net/socket.c:1325 [inline] SYSC_socket+0x16e/0x620 net/socket.c:1355 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x87b/0xab0 lib/fault-inject.c:149 SyS_socket+0x53/0x80 net/socket.c:1335 should_failslab+0x279/0x2a0 mm/failslab.c:32 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 slab_pre_alloc_hook mm/slab.h:422 [inline] slab_alloc_node mm/slub.c:2663 [inline] slab_alloc mm/slub.c:2745 [inline] __kmalloc+0xc2/0x350 mm/slub.c:3785 ==================================================================